Carbureter



R. S. SMITH.

CABBURETER. Amlcmon msu Mlm. 22. 19:5.

ludewtoz Patented May 11, 1920.

' Meson carbureter therefore UNITED STATES PATENT oFFicE.

REUBEN STANLEY SMITH,

0F MILWAUKEE, WISCONSIN, ASSIGNOR, IBY MESNE ASSIGN- MENTS, T0 IBB-16GB AND STBATTON COMPANY, 0F MILWAUKEE, WISCONSIN, A COB- POEATION 0F WISCONSIN.

CARBUBETEB.

SMITH, a citizen of the United States, re-` sidin at Milwaukee, county of Milwaukee, have invented new and tate vof Wisconsin, and useful lmprovements in Carbureters, of whiclthe following is a s ecification.

My invention relates to improvements in carbureters.

In the ordinary carbureters, liquid is fed from a reservoir into a so called float chamber, the inlet of which is provided with a rigidl connected float controlled valve, designe to maintain a constant level of liquid fuel in said chamber, and the outlet of which communicates with a fuel nozzle in a carbureting or mixing chamber adjacent to the float chamber. But it has been found that in carburetes of this type as heretofore constructed,if used on motor driven vehicles, the jolts, vibrations, and swinging movements of the vehicle are communicate to a greater or less extent to the float and valve. This tends to unseat the valve at times when the supply in the {loat chamber is already adequate or excessive and the becomes flooded.

The objects of In invention are to provide a carbureter or internal combustion motors, such as are used in connection with motor driven vehicles, in which a substantially constantlevel of liquid fuel may be accurately maintained under conditions of road travel; also to provide an eilicient carbureter of simple construction and light wei ht, adapted to the requirements of sma l ower units.`

Carlgureter flooding is most commonly experienced in the smaller units and simpler structures. My invention 1s therefore peculiarly adapted to overcome the diiculties experienced in `the operation of carbureters used on motor cycles and motor driven auxiliary wheels, such as are ernplov ed to propel bicycles or other vehicles wit which the motor wheels are connected.

In the drawings- Figure 1 is a vertical sectional view, drawn'to a major plane common to the axes of the float chamber and mixing chamber, with a fragment of the mixing chamber illustrated in full to show the air inlet, and with the fuel nozzle shown in section-on a minor plane, ex osing the nozzle ducts throughout their ength.

Speoication of Letters Patent.

Patented May 11, 1920.

Application led Hatch 22, 1915. Serial No. 16,010.

Fig. 2 is anfelevation of my improved carbureter, with one-half of the mixing chamber illustrated in vertical section on the line .fcof Fig. 1, and with a portion of the casing partially broken away on the other side to expose t e fuel nozzle and one of the air inlet ports.

3 is a plan view.

F1g. 4 is a fragmentary sectional view, drawn on line y--y of Fig. 3

.Fig 5 is a fragmentary cross sectional view, drawn on line s--z of Fig. 1.

Fig. 6 is a vertical sectional view of a float chamber embodying one of the rincipal features of my invention in mo ified form.

Figs. 7 and 8 are similar views showing further modifications.

Like parts are identified by the same reference characters throughout the several views. y

The float chamber 1 is provided with a removable cover 2, having a centrall disposed inlet port 3. The float cham er is provided with an inwardly projecting annular flange 5, which serves as a .guide for a cylindrical float 6. The oat 6 extends loosely into or through the annulus 5, and the relative dimensions of the float and annulus are such as to partially confine the liquid below the annulus as at a and secure a dash xlinot effect without binding frictional contact etween the float and the annulus 5. The Vfloat chamber is provided with an outlet port 7 ada ted to provide a deliver of liquid fuel rom a point in the float c am ber above the annulus 5. The fluid in the outlet is therefore not subject to lunger pressure exerted by the float upon t e fluid below the annulus.

A tube 9 extends vertically through the float, the interior of the tube being in communication with the s ace below the oat. A valve 10 controls t e deliverly of fluid fuel to the float chamber throng the inlet 3, said valve bein preferably supported upon the upper en of the tube 9 and rovlded with a stem 11, loosely sockete in said tube. The inlet port 3 is provided with an interior annular shoulder at 12, which constitutes a seat for the valve 10, the inlet port 3 being enlarged below said seat as shown. The tube 9 preferably extends into this enlarged portion of the inlet port 3,

coperative with the valve 3 and nulus 5 in supporting the float against latl ral movements. i

Relative vertical movements of the float in either direction are retarded or minimized by liquid fuel in the lower portion of the float chamber, which liquid must pass between the float and the annulus 5 in one direction or the other to permit such movement. A quick u ward movement of the float therefore ten s to create a vacuum below the annulus 5, while a quick downward movement of the oat creates a pressure in that portion of the chamber below the annulus.` The development of this pressure enables me to prevent such Heat vibrations from admittn an excess of liquid to the float chamber, y roviding means whereby this pressure may be exerted upon the valve to hold it to its seat. Owing to the fact that the valve is not positively connected with the float, but is loosely socketed therein, the valve tends to retain it's position upon the seat by inertia, but by extendin the socket or tube 9 downwardly through t e float and admitting thereto fluid from the spaceJ below the float, it is. obvious that any quick downward movement of the float sufficient to develop a ressure below annulus 5, will force some o l the liquid upwardl .in the tube 9 against the lower end of t e valve stem 11, thereby utilizing this pressure to hold the valve 10 to its seat 1 2. The valve stem 11 preferably extends substantiall to or belowthe level of liquid in the oat chamber, and as this stem serves as a plunger "in the tube 9, it is obvious that any upward movement of liquid in said tube will immediatel exert pressure upon the valve.

I do not imit the scope of m invention to the specic means above described for utilizing the downward pressure of a vibrating va ve su l'porting member or float in a reservoir or oat chamber to develop a counter pressure of the liquid in such chamber upon the valve andthereby prevent it from being unseated by vibrations of the valve supporting membia or float, at times when the supply of li ui in the iioat chamber is adequate. In ig. 6 I have illustrated a float 6 having a vertical passage 9* therein, which is of much larger 4diameter than the tube '9 shown in Fig. 1. -In this construction the valve stem 11 is comparatively small and is provided bwith a plun er or piston 13 naar its lower end whi substantially lls the passage 9. In this construction also, instead of providing the annulus 5, I construct a float chamber 1L` with a cylindrical downward extension 14 of reduced diameter, and the tube 9'? extends downwardly into this cylindrical portion 14, substantially fillin t e same, so that whenever the float 6Il is su jected to a quick downward vibration, some of the liquidin the cylindrical'extension 14 will be forced rrpwardly against the piston or plu er 13. e valve 10 is su ported from the oat b a rest 15, which a so serves as a guide for t e stem 11.

In Fig. 7 I have illustrated this feature of mg' invention embodied in a float chamber, w ich has an inlet 3* at the bottom, and a valve 1()b seatin with the pressure of the liquid in the in et ort. In this construction, the float 6" is a so arranged in dash ot relation to an annulus 5b projecting 1n wardl from the wallsjof the float chamber 1". he float is provided with a comparatively large tube 9", and the valve is suspended from the float by a'valve stemor rod 11". This stem also is rovided with a piston 16, substantially fi ling the tube 9h as shown. In this construction, the pressure developed in the li uid below the annulus 5b will o course ten to force the valve from its seat, but the piston 16 is of considerably lar er diameter, and this being also subject to t e liquid pressure exerted ,in an upward direction, the pressure upon the piston will be more than suilicient to counteract the downward pressure `u on the valve. @wing to the fact that the va ve in this construction closes with the pressure, the'necessity for counteracting the vibratory movements' of the float is not as eat as it is where the valve seats a ainst t e ressure of the liquid in the float c amber in et port. But my invention can be applied wherever the conditions are such that the valve is likel to become unseated through lloat vibration. In Fig. 8 a float 6 carries a depending piston or lunger 55, whereby it is brought into das pot relation to the wall of a reduced downward extension 14 off the float chamber. In this construction alsof I have shown the needle valve 10 .as rigidly connected with the float, the form of connection not being essential to the dash pot feature of my invention. l

The dash pot feature of my invention is also of value in preventing or retarding upward movements of the Heat. Such upward vibrations are alwa s `followed by dowm ward vibrations, an if notretarded, damage is also likely to result to the valve and its seat through the hammering eifect of the valve upon its seat in case a vibration should occur when the valve is open. Owing to the fact that the valve is not xed to the iloat, it it `obvious that it will also be little affected by lateral vibrations of the iloat,`such later l vibratory movements being extremely shov owing to the substantially close fit in the guides. It will of course be understood that the term piston as used in this description, does not implythat the member thus designated 4fits closely to the walls of the tube or passa in which it is located. The t will be su ciently loose to avoid friction.

The cover 2 of the float chamber may be Y provided with an upwardly projecting annular {ian 17 having a cap 18, pre erably threade thereon and inclosing achamber 19, the wall of which has an annular de ression 20 encircling the inlet port 3. A ltering screen 21 is clamped upon the flange 17 by the cap 18, and an sediment passing throu h this screen col ects in the channel 20. coupling nipple 23 affords means for connecting the float chamber with any suitable source of liquid fuel suppl The mixing chamber 25 is preirerably tubular in form and is provided with an air inlet port 26, which may be covered by a shield 27. An outlet port 28 is referably located on the opposite side of t e mixing chamber but oii'set from a diametrical line crossing such chamber from the air inlet port 26. In the construction shown, the exterior wall of the chamber 25 is flattened and provided with laterally projecting coupling ears 29 to facilitate connectin the carbureter with an internal combustion motor or` with a duct leading to the cylinder or cylinders thereof. The shield 27 tends to exclude dust. It is spaced from the outer surface of the wall of chamber 25 and forms an air admission passa e closed at top and sides and through whic passage air passes from the bottom upwardly to the port 26.

A piston throttle valve 30 is located in the upper portion of chamber 25 and is provided with an actuating stem 31, having a head 32 at its upper end and extending downwardly through the throttle valve 30 and the cham ber v25 to an exterior point. A compression spring 33 is interposed between the head 32 of the stem and a suspended stop 30' which is adapted to extend into the open upper end ofthe valve when the latter is in raised position, said spring being also preferably partially socketed in the 'valve when the latter is in normal or raised position. A downward movement of the throttle valve simultaneously and progressivel closes the air inlet 26 and the mixture out et 28. VThe air inlet is, however, enlarged downwardly and is formed with a view to securing aV propermixture during the various stages of valve movement. The exposed lower end of the valve stem 3l is of course adapted to be connected for operation from any desired point at which manual power may be ap plied. The spring 33 tends to hold the throttle valve 1n open position, from which position it is moved toward closing position by a downward pull applied to the stem 31.

The mixin chamber and float chamber are connecte (preferably integrally) by a member 35, which has a tubular openlng therethrough to receive a removable nozzle member 36 threaded into the lower end of the member 35 and having an up er end portion 37 of reduced diameter, w ich constitutes the nozzle proper, the same having a longitudinal nozzle passa e 38 for fuel def livery. The upper end o this nozzle member extends to the interior of the mixing chamber, and the fuel nozzle assage 38 is so disposed as to deliver the fue along a dia onal line in the direction of the interior w51 of the mixing chamber 25 between the air inlet 26 and the outlet 28. The outlet port 7 of the float chamber leads to an annular cavit 4Q `in the nozzle member 36, from whic cavity cross ducts or ports 41 extend inwardly and communicate with the nozzle passage 38. This nozzle passage has an annular shoulder at 43,formin a seat for a needle valve 45, the latter hav1n a stem 46, threaded into the lower end o the nozzle member and extending throu h a packing nut 47. The shoulder, formeby reducing the upper end of the nozzle member 36, seats against an annular shoulder 48 formed on the interiorwall face of the member 35.

Above this point the nozzle member does` not fill the opening in the member 35 and an annular passage 50 is therefore formed, which leads upwardly from the shoulder 48 to the interior of the mixing chamber 25 and constitutes an air nozzle. Air inlet ports 51 extend laterally through member 35 and communicate with 'this passage 50, whereby, when a partial vacuum is created in the chamber 25 by suction of the motor piston an atomizin current of air will be delivered past the out et of fuel nozzle 37, which will create an additional suction at the nozzle outlet and facilitate breaking up or atomizing the liquid fuel discharged therethrough.

The fuelV will be additionally atomized by l striking the opposin wall of the mixing chamber. The shiel 27 will prevent any of the liquid from being wasted by rebounding through the air inlet 26. Any such liquid will adhereto the shield and be vaporized by the entering current of air, either during the same vor the succeeding suction stroke.

It Will be observed that the nozzle' duct 38 discharges the liquid not only angularly across the mixing chamber 25, but also delivers it obliquely with reference to the stem 31. The air enterin through air nozzle passage 50 is delivere in the same direction and owing to the fact that the wall of chamber 25 is curved, a whirling current is thus developed in the mixing chamber, which greatly facilitates mixing the air and hydrocarbon.

I claim- 1. A carbureter, including a float chamber provided with an inlet, in combination with a valve controlling deliveries through said inlet, a float normally controlling sald l 2. A carbureter, including a lioat cham-` ber provided with an inlet, in combination with a Valve controllin said inlet, a float normally .supporting said valve, and meansY ment being such that the vibratory 1movements of the float are limited by the partial confinement within the float chamber of a portion of the liquid in which the float is supported.

5. A carbureter, including a float chamber, a float therein and in dash pot relation thereto, and a fuel inlet valve loosely connected with the float, the arrangement being such that the vibratory movements of the fioat are directed by partial confinement of a portion of the liquid in the float chamber.

6. A carburetor, including a lioat chamber, a float therein, in dash pot relation thereto, a valve loosely connected with the float and exposed to pressure of the liquid in the space below the float, whereby, when the float vibrates, its downward movement will develop liquid pressure upon the valve to hold the latter to its seat..

7. A carbureter, including a float chamber, in combination with a float, a valve, and means for utilizing quick movements of the float in one direction to apply fluid pressure to the valve in the other direction.

8. A carburetor, provided with a float chamber having a downwardly discharging fuel inlet port, in combination with a float in said chamber, and a needle valve loosely socketed in said float and seating in said inlet ort.

9. carburetor, including a iioat chamber provided' with an inlet at the top, in combination with a float in said chamber in dash pot relation thereto, and a valve seated in said inlet and loosely supported by the Hoat, the float beingr free to vibrate independently of the valve.

10. A carbureter, including a float chamber, in combination with a float in said chamber, an annulus projecting into the float chamber around said float to form a dash pot, said chamber having an outlet above said annulus and an inlet in its top, and a valve loosely socketed in the float and controlling the inlet.

11. A carbureter, consisting of the combination of a chamber provided with a. centrally located fuel inlet port in its upper portion, a float in said chamber provided with a tubular socket centrally located diannulus located below the normal level of the liquid in said chamber, and a float in said chamber projecting looselyY through said annulus.

13. A carbureter, including a float chamber, a float in said chamber andin dash pot rrelation thereto, and a fuel inlet valve sup- `ported by the float, whereby the vibratory movements of the float are limited by the partial confinement of a portion of Vthe fluid in the float chamber.

14. A carbureter, including a float chamber and a float seated in said chamber in dash pot relation thereto, said float chamber having an outlet located at a point exterior to the dash pot portion of the chamber.

15. A carbureter, consistingl in the combination with a float chamber provided with a fuel inlet in the central portion of its to'p, a float, a needle valve loosely socketed in the float at the vertical axis thereof, with its oint adapted to be seated in said inlet, an an annular projection on the inner wall of the float chamber near the bottom of the float, through which the float projects in dash pot relation thereto.

16. A carbureter, including a float chamber rovided with a top wal having a vertica ly disposed inlet port, the walls of which are annularly shouldered at an intermediate point to form a valve seat, a float in said chamber, provided with an upwardly projecting tubular stem projecting into said port and guided by the walls thereof below said seat, a valve adapted to close upon said seat and provided with a stem loosely socketed in the tubular float stem, and means for loosely guiding the lower end of said iioat.

17. A carbureter, including a fioati chamber provided with a top wall having a vertically disposed inlet port, the walls of which are annularly shouldered at an intermediate point to form a valve seat, a float in said chamber, provided with an upwardly projecting tubular stem projecting into said port and guided by the walls thereof below said seat, a valve adapted to close upon said seat and provided with a stem loosely socketed in the tubular float stem, and means for loosely guiding the lower portion of said 'float and retarding displacement of liquid hydrocarbon from the under side thereof, said float chamber having an outlet located above the liquidl retarding means, substantially as described.

. 18. A carbureter comprising a float chamber, in combination with devices for maintaining a substantially constant fuel level in said float chamber, said devices including a float in dash pot relation to said float chamber, whereb a portion of the fluid is in partial confinement in the float chamber, and serves to limit the vibratory movements of the float. I

19. A carbureter including a float chaln ber, a float therein in dash, pot relation thereto, a valve loosely connected With the float, and means for utilizing vibratory movements of the float to apply pressure of liquid from the space below the float to the `valve when the float moves away from valve holdin position.

20. carbureter comprising in combina-- tion a float chamber and devices for maintaining a substantially constant fuel level in said float chamber comprising a float, a fuel inlet valve having lost motion connection with said float and arranged to be held in closed position by fluid pressure from beneath the float when the float moves quick y downward, and adapted to be normall held closed by the float when the liquid' fuel in said float chamber attains a pre-.determined level.

In testimony whereof I ailix my signature in the presence of two witnesses.

REUBEN STANLEY SMITH. Witnesses LEVERETT C. VHEELER, IRMA D. BREMER. 

